Drilling machine clamp



A. R. LAWRENCE DRILLING` MACHINE CLAMP Fied Aug. 14,1934

4 Sheets-Sheet l if @ze INVENTOR nlzz'a la7 laure/142 Y MQW,

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pr 7,1936. A. Rt LAWRENCE 2,036,483

DRILLING MAHINE CLAMP Filed Aug. 14, 1934 4 sheets-sheet 3 INVENTOR pril 7, 1936. A. R. LAWRENCE DRILLING MACHINE CLAMP 4 sheets-sheet 4 Filed Aug. 14, 1934 Patented Apr. 7, 1936 UNITED STATES DRILLING MACHINE CLAMP Archibald R. Lawrence, Montreal, Quebec, Canada Application August 14, 1934, Serial No. 739,753

25 Claims.

This invention relates to supporting devices for supporting drilling machines, or rock drills, such as are used in mines for the purpose of drilling holes in rock or other earth formations to facilitate the employment of explosives used in breaking up such material, or otherwise.

Such drilling machines must be firmly supported while in operation to permit drilling effectively. It is customary to support drilling machines of the drifter type on a cross arm which is attached to a column, or stoping bar. 'I'he column consists usually of a pipe about 31/2 inches in diameter which is set up in proximity to the face to be drilled and is generally secured in place by means of a jack screw at one end of the column which forces the opposite ends of the column respectively against the oor and ceiling adjacent the face to be drilled. The cross arm is usually a short length of pipe about the same size and is attached to the column at right angles by means of a suitable collar, or coupling. The drilling machine is mounted on this cross arm by means of a clamp. The clamp is secured to the cross arm usually by means of two bolts, and the drilling machine is secured to the clamp by means of another bolt. A special extra long wrench is used for tightening and loosening the nuts on these bolts.

In the ordinary course of drilling, the drilling machine has toy be shifted frequently in order to drive the holes at the desired locations, and the amount of labor involved in shifting the clamp horizontally on the cross arm and in changing the angular position of the drilling machine both in the vertical and the horizontal plane, is very considerable as it requires great physical strength both to loosen and tighten the nuts, and considerable time is consumed in this work. The general practice is to provide the operator with a helper .whose principal work consists in handling the wrench.

Inasmuch as the direction of the resultant of the forces applied to the supporting device `during the operation of the drilling machine is 'transverse to the longitudinal center line of the cross arm and applied to the supporting device above or below the cross arm, the supporting device must be provided with means for gripping the cross arm suicient to prevent slipping of the supporting device which would allow it to rotate about the cross arm. The moment of forces tending to overturn the supporting device, that is, to turn it, about the cross arm can be tremendous in certain positions of operation, as, for in- (Cl. Z-51) stance, when the drilling machine is retracted to the rear of the carriage.

To effectively resist such tremendous overturning moment the supporting device must grip the cross arm with a pressure of the order of 10,000 pounds per square inch. To obtain such clamping pressure, utilizing the fluid pressure ordinarily available, such as the pressure of the water or compressed air used in mines in connection with rock drilling which is about pounds per square inch, and at the same time to` avoid the use of large, cumbersome operating cylinders, and keep the weight of the supporting device and its dimensions commensurate with the size of the drilling machine itself, presents a considerable problem, and the provision of such a supporting device is the object of the present invention.

A further object of the invention is to provide a fluid pressure operated supporting device for drilling machines which is capable of producing ample clamping pressure both for holding the 1 device upon the cross arm, and for holding the drilling machine against swinging, without rendering the device cumbersome and diflicult to handle, and also without restricting the range of drilling of the drilling machine.

Another object of the invention is to provide a iiuid q pressure operated supporting device for drilling machines in which failure of the supply of uuid pressure will not cause the device to release its hold on the cross arm.

My invention is illustrated by way of example in the accompanying drawings which show twoembodiments of the invention, and the invention will be understood by referring to these drawings in connection with the following detailed description. In these drawings:

Fig. l represents a View in elevation of a column and cross arm with a. drilling machine supported thereon by my improved supporting device or clamp, the drilling machine and clamp being shown in end View;

Fig. 2 represents a view of the clamp in central vertical section taken on line 2 2 of Fig. 1;

Fig. 3 represents a top View of the clamp;

Fig. 4 represents a view of the clamp in side elevation;

Fig. 5 represents a sectional View of the clamp taken on the planes represented by the broken line 5 5 of Fig. 4.

Fig. 6 represents a sectional View of the clamp u taken on the planes represented by the broken line 6 6 of Fig. 4;

Fig. '7 represents a bottom View of the clamp with a fragment broken away and shown in sec- Lil tion to illustrate one of the fluid control valves;

Fig. 8 represents a horizontal sectional View taken on the plane represented by line :5 8 of Fig. 2;

Figs. 9 to 13 inclusive are fragmentary sectional views taken on the several planes indicated in Fig. 8 for the purpose of showing the fluid passageways, Fig. 10, however, showing also a safety feature;

Fig. 14 represents a view in vertical central section of a modied' form of my improved supporting device; and

Fig. 15 is a top view of the modification shownA in Fig. 14. y

Referring now to the accompanying drawings, Fig. 1 illustrates a fluid actuated percussive drill I mounted upon my improved supporting device 2, which, in turn, is carried upon a cross arm 3 consisting `of a short length of pipe. Cross arm 3 is attached by means of a collar, or coupling 4 toa'vertical column, or stoping bar 5 which is set up near the face of the formation which it is desired to drill. Column 5 is held in place by means of a. jack screw 6 at its lower end, which forces the foot of the column against the oorl and the head of the column against the ceiling 8.

The drilling machine I has a carriage 9 along which it is advanced by means of the feeding handle I0 as the depth of the hole increases. These drills are usually operated either by air or water under pressure and in the present instance, drill I is supplied with compressed air through hose II. The carriage 9 of the drilling machine has at its bottom a conical base I2, thisbeing the standard way of providing for the attachment of such Adrilling machines to their supports.

My improved supporting device, or clamp coinprises a pair of fluid pressure cylinders, IL3 and I4 adapted respectively to actuate mechanism for securing the supporting device upon cross arm 3, and for securing the drilling machine to the supporting device, as will be hereinafter described in detail. These cyiinders are placed approximately in line with one another, though spaced apart, as shown in Figs. 2 and 4 and are mechanically connected by means of two thin parallel plates I5 and I6. Cylinder I4 is somewhat smaller than cylinder I3, but both are of the same order of `size as the diameter of the cross arm 3.

The two plates I5 and i6 extend upwardly above cylinders I3 and I4 a sufcient distance to accommodate a transverse member I'l, preferably of cylindrical form, which has an aperture I8 therethrough to accommodate the supporting' arm 3; Directly above member II is a platform I9 upon which is received the bottom of conical base I2 of the drilling machine I. 'Ihese parts, namely cylinders I3, I4 plates I5, I il, member I'I and platform I9 are preferably made integral by casting them all in one piece, but if desired, they may be made as a composite structure in whole or in part and be suitably secured to one another by means of welding, or otherwise.

Platform I9 is provided at the left as viewed inV Figs. 2, 3 and 4 with a projection having a shoulder 2U sloped and curved to conform with the conical surface'of conical base l2 of the drillingmachine I. Opposite shoulder 20 and threaded into a boss 2| formed on member I'I is a stud bolt 22 which carries a swing lever 23. The upper end of swing-lever 23 is turned horizontally and provided with a shoulder 24 adapted to coact withshoulder 20 in securing the conical base I2 of-,the drilling machine to platform I9.

Swing lever 23 is arranged to pivot for a limited swinging movement in a vertical plane about stud 22, being held thereon by means of nut 25. The lower portion of swing lever 23 extends well below the cross arm 3 and is acted upon by the piston rod 26 of air cylinder I4.

The admission and release of compressed air to the cylinder I4 is controlled by means of a valve handle 21,' and in operating the device to clamp the conical base I2 of the drilling machine so as to hold the machine in position for drilling, the nut 25 is first turned by the lingers so as to bring shoulder 24 lightly against the side of the conical base I2. The threads of nut 25 and bolt 22 are lcosely fitted so that nut 25 can be easily turned by hand to initially place the The movement of valve handle 2'I to a position approximately at right angles to that shown in Fig. 2 cuts off the supply of air to cylinder I4 and' places the cylinder in communication with the atmosphere, thereby releasing the clamping mechanism.

In View of the adjustment of shoulder 24 into` initial clamping position by means of nut 25'before applying the air pressure, only a small relative motion between shoulder 24, shoulder 20 and platform I9 is required in order to firmly clamp the drilling machine in place. On account of the fact that shoulder 24 is located close to the bolt 22, and the piston rod 26 applies its force to swing lever 23 at a considerable distance from bolt 22, adequate clamping pressure againstY the conical base I2 is obtained with the use of a comparatively small cylinder. These are iinportant ccnsiderations from the standpoint of lightness of weight and facility of handling.

It will be understood that the length of curved shoulder 29 is sufficient when shoulder 2'4 is in even loose engagement with conical base I2, to prevent sidewise movement of base I2`and to hold the drilling machine upon the supporting device 2. With the parts loose, the drill can of course be swung in a horizontal plane asdesired. In order to insure that the drilling machine can'- not turn upon platform I9 while the machine is in operation, the faceV of shoulder 24 is provided with a plurality of teeth 23` which provide a surer grip'upon the surface of conical base I2 than if the shoulder 24 was smooth.

Swing lever 23 is pivoted on bolt 22 by means of the aperture 29 and the curved surfaces 30 which rock on the inner face of nut 25, thereby reducing friction and increasing the effective clamping pressure. Bolt 22 is of sufcient length to permit the device 'tof accommodatev conical bases I2 of different size.

The piston 3l of cylinder I4 may be made in any suitable manner, but preferably consists` of a cup shaped leather washer clamped between two metal plates on piston rod 26` as shown. Cylinder I4 is closed at its outer end by means of a head, or cap 32 which is threaded internally. into cyiinder I4 so asv to reduce the number of projecting parts tending to catch on various objects during'the use of thedevice.' The lower'A end of swing bar 23 is preferably provided with a rounded lug as shown for coacting with the end of piston rod 26, the lower portion of the swing lever being guided between two ears 33 projecting outwardly from member I1 as shown in Figs. 2, 4 and 5.

The supporting device 2 is held in position on the arm 3 by means of a pair of narrow fixed lugs 34 extending inwardly from the inner surface of member I1 and by means of a radially movable narrow toothed jaw, or gripper 35 preferably of hardened steel, which is moved inwardly by means of a cam 36 on a lever 31 which is pivoted by means of a rod 38 between the plates I5 and I6. The lever 31 is moved by means of a piston rod 39 and its coacting piston 46 located within fluid pressure cylinder I3. Lugs 34 and toothed jaw 35 extend laterally parallel with the axis of cross arm 3 for a distance equal to the spacing between plates I5 and I6 as shown in Fig. 5.

In the embodiment of the invention here illustrated, the clamping, or gripping action on cross arm 3 is, therefore, provided at three points spaced about 120 apart, the faces of lugs 34 and toothed jaw 35 being relatively narrow so as to increase the pressure per square inch exerted by them against the surface of cross arm 3.

Cam 36 extends the full length of toothed jaw 35 so as to sup-port the jaw throughout its entire length, and the piston rod 39 engages the center of lever 31, an extension 4I being provided for this purpose as shown in Fig. 6. Lever 31 pivots on rod 38 by means of ears 42 one at each side. Toothed jaw 35 slides loosely in a rectangular aperture extending through the wall of member I1 and the jaw is provided with a head as indicated, to retain it within this aperture.

The extremely large clamping pressure required to hold the supporting device upon arm 3 during the operation of the drilling machine is provided without using a working cylinder of prohibitive diameter and weight by multiplying the force exerted by piston 49 of cylinder I3 by means of lever 31 and cam 36. The multiplication of pressure is caused not only by the fact that the cam 36 is closer to pivot rod 38 than piston rod 39, but also because of the wedging or cam action of cam 36 as it moves over the surface of the head of toothed jaw 35. That is to say, the extremely small radial movement of toothed jaw 35 necessary for clamping is produced by means of a cam, or wedge operating upon the outer surface of the toothed jaw, this wedge, or cam being actuated by means of a comparatively long lever 31. In this way, there is enormous multiplication of the force exerted by piston rod 39 as will' be readily appreciated by considering the small movement of toothed jaw 35 in comparison with the length of stroke of piston 46.

Piston 40, like the piston of cylinder I4, may be of any suitable construction, but preferably consists of a cup shaped flexible washer held between two metal discs by means of a nut on the end of p-iston rod 39 as shown in the drawings. The outer end of cylinder I3 is closed by means of a head, or cap, 43 which is threaded into the interior of the cylinder and preferably made flush with the outside diameter of the cylinder.v Head 43 is provided with a square projection 44 for the application of a wrench for placing and removing the head.

In order to take the reaction of the thrust of piston rod 39, a pair 'of thin, narrow struts 45 are cast integrally with the inner end of cylinder I3, one on each side of the piston rod 39, and these struts extend inwardly and join the central portion of the lower wall of member I1. These Struts also serve to protect the operators lingers from being jammed in the mechanism while manipulating the valve handles 21 and 64.

As the weight of the drilling machine I is usually unbalanced on the axis of supporting arm 3, it is important to provide means for maintaining the supporting device 2 in clamped relation to arm 3 should the supply of pressure uid fail. This is accomplished by mechanism which is shown in Figs. 2 and 10. Referring rst to Fig. l0, a third fluid pressure cylinder 46 of small diameter is provided having a piston 41 which is urged downwardly by the pressure fluid against helical spring 48 placed beneath the piston and bearing at its lower end on a closing cap 49 for the cylinder. A vent 50 is provided in this cap to permit the ready egress and ingress of air out of and into the space below piston 41.

A piston rod 5I extends upwardly from the piston 41 and terminates in an enlarged head 52 which moves vertically in the space between the straight or left hand side of lever 31 as viewed in Fig. 2 and a vertical shoulder 53 formed by a lug on the inner side of plate I5. Under normal conditions, that is to say, when fluid pressure is supplied to the supporting device, it is admitted above piston 41, thereby compressing spring 48 and holding head 52 in its lowermost position as shown in Fig. 10, and in full lines in Fig. 2. In this position, lever 31 is free to move by the application or release of fluid pressure from cylinder I3. Should the uid pressure supply fail, however, spring 48 will force piston 41 and head 52 upwardly into the dotted position shown in Fig. 2, and assuming that the toothed jaw 35 was in engagement with cross arm 3, when the pressure supply failed, the toothed jaw will be held in this position by the wedging action of head 52 between shoulder 53 and lever 31.

The fluid passageways and valves of the supporting device will now be described. All these passageways are preferably cored, or drilled in the body or frame of the device so that there are no external pipes to be damaged by mechanical injury. These passages are shown more particularly in Figs. 8 to 13 inclusive and Fig. 4. In the present embodiment, air under pressure is supplied through a hose 54 (see Fig. 1) which is connected to the same supply line as hose II for the rock drill I. Hose 54 is connected by means of union 55 to a short length of pipe 56 in which there may be placed a cut oli valve 51 if desired, pipe 56 being threaded into the lower end of a vertical 4, 8 and 9.

Passageway 58 communicates at its upper end as shown in Fig. 9 with a horizontal passageway 59 extending crosswise of the supporting device as shown in Fig. 8. This passageway communicates at one end with an operating valve 60 which controls the admission and discharge of fluid to air cylinder I3 for operating the mechanism which clamps the device to cross arm 3. The opposite end of passageway 59 communicates with a passageway 6I which extends to the right hand end of the device and supplies uid to the cylinder I4 for operating the mechanism which clamps conical base I2 of the drilling machine, as will be more fully described below. Side plate I5 is thickened at the bottom to accommodate passageway 58 shown in Figs.v

passageway 6 i as shown in Fig; 8, and inthe em'- bodimentillustrated'all of these various'passageways are vshown as having been drilledv in the body of' the device4 and vconsequently the ends of these passageways where the drill entered are closed by means of plugs 6-2.

Operating valve 60 for cylinder' I3 is a conical member (Fig. 9) mounted upon the end of' a rotary valve stem 63 androtated by means of a handle 64 secured near thev outer end of stem 6-3. Valve 60 is seatedin a conical seat 65 provided in the body of the supporting device adjacent the inner end of cylinder I 3. Valve 60 is provided with a through port 66 which in the open position of the vvalve is in alinement with passageway 59 and a similar passageway 61 on the opposite side of the valve member which is provided in the wall of cylinder I3 and which communicates by means of an opening 68- with the interior of cylinder I3 adjacent its outer end.

Valve B andvalve handle 64 are shown in the drawings in the open position in which air is being supplied to cylinder I3 to clamp the device upon cross arm 3. When it is desired to release the device from cross arm 3, valve handle B4 is turned inwardly in the direction of the arrow shown in Fig. 8 by an angle of about 60. This cuts oi through-port 66 from supply passageway 59, brings the opposite end of through-port 66 into communication with a small exhaust port 69, and also moves a small port 1I)y in valve 69 to a position opposite passageway 61 so that the air within cylinder I3 can discharge therefrom `through passagewayvl, small port 10, the outer end of through-port 66 and exhaust port E9 to the atmosphere.

Valve 6I! and itsstem 63 are inserted and removed by removing a plugy 1I which is threaded into a cylindrical opening at the outer end of conical valve seat 65. A passageway 'I2 to the atmosphere is provided in the front-wall of cylinder I3 so that the movement of' piston 49 will not be aiected by air trapped on the right hand side of it.

The valve handle 21 for controlling the operation of air cylinder I4 which clamps the conical base I2of the drilling machine, is attached to the stem 13 of a second conical valve- 14 shown particularly in Figs.. 7, 1l and 4 and located along- L:side of cylinder I4 near the bottom of the cylinder.

The conical seat for valve 14 has a cylindrical base 15 at its right hand end which is closed by means of a screw plug 16, and a helical spring 11 is interposed between plug 16 and the end of valve 14 to maintain the valve against its seat. Air for operating cylinder I4 is admitted to valve 14 through passageway 18 from passageway 6I, passageway 19 communicating with bore 15 beyond the end of valve 14. Valve 'I4` has an axial passage 19 which communicates at its end with a lateral passage adapted, when the Valve is in its open position as shown in Figs. 2, 4, 6, 8, 11, 12 and 13, to communicate with a port'BI opening into cylinder I4 as shown particularly in Fig. 12.

When valve 14 is moved to the position shown in Fig. '7v the air supply is cut off from cylinder I4 and the cylinder is exhausted to atmosphere so as to release the clamping, action of swing lever 23. In order to accomplish this, the valve handle is swung through an angle of approximately 45 and thisflrst of all cuts off lateral valve passage 8D from port 8|, thereby cutting off the -supply of air toA cylinder I4. Thena small through lateral passage 82V in valvef 14' isy brought intol alinement withsimilar small passageways 8'3- and T84-, shown inv Fig. 13, which places the interior of cylinder I4 in communication withv atmosphere.

Inasmuch as the valves 60 and'14 are sofwar-v ranged that their operating handles 64 and 21,.

respectively, are within the space between the inner end of cylinders I3 and I4, these handles are projected to a large degree against mechanicalV injury during the operation or moving about of the drilling machine and clamp from place to place in the mine and elsewhere. is also readily accessible to the operator in every position in which the clamp may be used.

Referring now to Figs. 14 and 15 of the accompanying drawings, there is here illustrated a modined form of my improved supporting device. In this form the frame is provided at the top with a platform I 9a for the conical base I2 of the drilling machine, and at the left hand side with a iiuid pressure operated cylinder I 3a provided withV ings adapting the supporting device to receive thel cross arm 3. Y

The upper end of member 88 is apertured to loosely receive the outer end of piston rod 39a upon which a nut 99 is threaded and by means of which piston 49a is enabled to draw member 88 tightly about cross arm 3to clamp the supporting device thereon.

A hardened steel toothed insert 9| is mounted in the upper portion of semicircular opening 86, this insert extending in length throughout the width of the supporting device and having its teeth projecting inwardly beyond the surface of opening 86. Diametrically opposite insert 9| is a secondhardened steel insert 92 which preferably is placed near the bottom of swingable member 88 close to the pivot pin 81. VLug 92 has teethy projecting inwardly beyond the surface of semicircular opening 89 and this insert also extends in length throughout the width of the supporting device.

In operation, this form ofsupporting device is somewhat different from the supporting device shown and previously described in connection with Figs. l to 13 inclusive, thev principal diierence being that the nut 90 which turns readily onV the end of piston rod 39a is screwed up by hand to bring inserts 92 and 9! into approximate con-Y tact with the surface of cross arm 3 to place the parts in initial clamping position. Then air is admitted to cylinder I3a' to force inserts 92 and SI into clamping relation with cross arm 3 so as to hold the drilling machine in operative position. n

This permits cylinder i3d to be constructed for a. considerably shorter stroke than cylinder I3.

As in thev case of the device previously described,V

the pressure produced by piston 449d. through the use of pivoted clamping member 88 is multipliedy by placing insert 92 relatively close to pivot pin B1 and the pressure per square inch exerted byV are somewhat different from that'of the cylinder I3. For example cylinder I3a, instead of'bein'gl castasa part of the frame-83 is a separate-cupthe Their locationV shaped stamping or casting and is threaded as indicated at 93 into a recess formed in frame 85. Inasmuch also as the fluid pressure is admitted to the inner or piston rod side of piston 49a, a gland, or stuiiing box 94 is provided for piston rod 39a. The hose 54 from the air supply is connected through a union 55 to a short length of pipe 95 in which is a two way valve 95, and which at its upper end is screwed into the lower end of a cored passageway 91 which communicates with the interior of cylinder I3a.

Valve 96, it will be understood, is so constructed that in one position it permits air to ilow from hose 84 into cylinder ISa, and in another position it cuts off this air supply and opens cylinder I3a to the atmosphere so as to release the air pressure from piston 4011.

In this modified form of supporting device, the conical base I2 of the drilling machine I is clamped upon platform I9a by hand instead of by automatic means. The drilling machine base I2 ls held on platform I9a by means of a curved shoulder 20a similar to shoulder 2U shown in Figs.

y2 and 3, and by means of a second shoulder 98 which is similar to shoulder 24 except that its lower portion is apertured at 99 to slide upon stud bolt |09, and it is moved into clamping position entirely by means of a nut IIJI which is manipulated by a hand wrench in the usual manner. To prevent'the part carrying shoulder 98 from falling out of position when it is loosened from the drilling machine base I2, this part is arranged to slide within a recess |02 formed in the edge of platform I9a.

In the form of construction shown in Fig. 2, the supporting arm 3 is gripped at three spaced points, whereas in the modification shown in Fig. 14 the arm is gripped at only two points. It will be understood that two point gripping may be employed in connection with the supporting device as shown in Fig. 3 and, vice versa, that three point gripping may be used with the device of Fig. 14.

'I'hese additional gripping points, lugs, or toothed inserts, may be placed either on the body or frame of the device of Fig. 14 or upon the pivoted clamping member 88. It is preferable, however, to place them on the body and provide only a single gripping point on member 88 located close to the pivot. For certain classes of work more than three gripping points may be employed, or the lugs 34, for example, of the device shown in Fig. 2 may be omitted and the clamping done by means of the toothed jaw 35 and the inner surface ofA member II. Also for certain classes of work the teeth may be omitted from the gripper and/or the gripper may be comparatively wide. It will be understood that other changes, also, may be made within the scope of the appended claims.

Supporting devices constructed in accordance with my present invention have been successfully used in mines under actual drilling conditions. They are appreciated by the drilling machine operators because of the fact that they weigh substantially no more than the ordinary type of hand operated clamp, because they hold the drilling machine securely in place so that it is irnmovable during operation, because the clamping and unclamping operations are easily and quickly accomplished, and because they enable the drilling machine operators to drill a greater hole footage in a day than it is possible to drill with the hand-operated type of clamp.

I claim:

1. In a drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said device having an aperture adapting it to be received upon a supporting arm, clamping means associated with said aperture, a fluid pressure device, and force-multiplying mechanical means connecting the fluid pressure device and said clamping means thereby causing said clamping means to secure said supporting device upon the supporting arm.

2. In a drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said device having an aperture adapting it to be received upon a supporting arm, a single narrow faced gripping member arranged for radial movement to clamp said arm in said aperture, a iiuid pressure device and force-multiplying mechanism connecting the uid pressure device and said gripping member to actuate the same.

3. In a drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said frame having an aperture adapting the frame to be received upon a supporting arm, a pair of lugs projecting inwardly from the wall of said aperture, a single narrow faced movable gripping member opposite said lugs, a uid pressure cylinder having a movable element, and a force-multiplying mechanism connecting said element and said gripping member to move the same toward said lugs and exert clamping pressure suflicient to secure said supporting device upon said arm.

4. In a drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said frame having an aperture adapting the frame to be received upon a supporting arm, a movable gripping member, guides for said member permitting radial motion thereof with respect to said aperture, a cam coacting with said gripping member to move the same in said guides, a fluid pressure cylinder having a movable element, and force-multiplying mechanism connecting said element and said cam to cause said gripping member to clampingly engage said supporting arm.

5. In a drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said frame having an aperture adapting the frame to be received upon a supporting arm, a movable gripping member, guides for said member permitting radial motion thereof with respect to said aperture, a lever pivoted adjacent said guides having a cam coacting with said gripping member, and a fluid pressure cylinder actuating said lever so that the force applied to said lever by said cylinder is multiplied Sulliciently to cause the gripping member to secure said supporting device to said arm.

6. In a drilling machine supporting device, a

frame having an aperture for receiving a cylindrical supporting arm, means for removably securing a drilling machine to said frame, a fluid pressure cylinder having a piston whose axis is at right angles to the axis of said aperture and spaced therefrom, a lever actuated by said piston and pivoted on the frame of the supporting device, a movable jaw projecting into said aperture, guiding means for permitting said jaw to move radially with respect to said aperture, and a cam on said lever close to the pivot thereof coacting with said jaw to force the same into clamping engagement with said arm.

'7. In a drilling machine supporting device, a

i is

frame for securing a driliing machine thereto, said frame having a .curved recessadapted to partially surround a supporting arm, amember pivoted on said frame close to said recess and 5 vadapted te coact therewith in surrounding said .supporting arm, said member having a single nartoothed'gripping portion, said grippingportion. being `the only part of said pivoted member @toen'gage'said arm, and a 'uid pressure cylinder l vhaving a .piston rod connected with said member on the opposite side of the supporting Varm from 'said pivot kwhereby the force applied by said ipiston rod is multiplied sufliciently to cause said 4'toothed portion Yto engage the supporting arm f .l5 `with suci'ent pressure to hold the drilling mai chine in operative position. f8. In a .drilling machine supporting i device, -fluid 4pressure operated mechanism for clamping said 'device inoperative position upon a supporty:2'0 `ing arm,1and'iiui'd .pressure responsivemeans for preventing the release ofi-said clamping means in yfthe event of 'failure ofthe pressure iiuid supply. *9; In :a drilling V'machine supporting device, `clampingfmeansfor securing said device in opler'a'tive position Vupon a supporting arm, a member'movable by fluid pressurefor actuating said clamping means, a locking device for locking said member inv clamping position, means for urging said-member toward looking position, and fluid .fan vpressure actuated means for holding said locking 'f'device out of locking position, whereby failureof Ime-'supply' 'o'f fluid pressure is 'prevented from "causing'the Vclampingmeans to release its hold on theesupportingarm;

f. -10. drilling. machine .supporting device havfing aplatform for receivingthe base ef adrillf ing machine, iixed and movable jaws coacting 'Withsaidbase to clamp the base on said platffo'rin, a/manually adjustable nut for placing said Yx'novable javv'in initial clamping position, and fluid pressure operated means for moving 'said jaw to iinalolamping position.

"Ilfn a drilling machine supporting device having a platform for receiving the base of the drilling machine, a fixed jaw 'coacting with said 'bas'eya threaded projection at the side of said platform, an apertured lever' loosely iitting upon saidthread'ed projection, said lever having at its .upper end a -shoulder-iY adapted to coact `With the conicalsurfaceof. said'basaa vnuton said threaded projection adapted rto bring said shoulder into contact with said base, said lever having an extension on the oppositesideof said threaded projection 'fromzsaid shoulder, and a fluid pressure #cylinder 'having a piston coacting with said exvtension 'to force Vsaid shoulder into clamping engagement with said conical base.

.12. 1A drilling machine'supporting device coinpri'sing a pair 'of axially spaced fluid pressure cylinders arranged substantially in line With one another andfconnected by :a structure comprising -t'vvofspace'd parallel plates and a member joining saldi plates having an aperture 'for receiving a cylindricalsupporting farm, a platform above said `member ladaptedto receivethe base of a drilling machine, clamping mearisactuated by one of said'iluid pressure cylinders for clampinglyaengaging said base, and clamping means actuated by the .other of said rluid pressure cylinders for Yclarnpingly engaging said supporting arm.

'113. Adrilling machine supporting device :comprising a pair of axially spaced 'fluid pressure Y`cylinders arranged substantially iniine with one another and connectedbya structure comprising Y:two spaced parallel plates-anda member joininders having `handles operable Within Y between said cylinders.

Ylay-to causethe gripping member to secure ingsaid plates having an aperturefor receiving a cylindrical supportingY arm, aeplatform r'above said member adapted to receive the base of ia drillingV machine, clamping means actuated by Vone of said fluid pressure cylinders for ciampingly engaging said' base, and clamp-ing means actuated bythe other of said fluid pressure cylinders YYfor clampingly engaging said Ysupporting arm,

Yand valves for controlling said uid pressurecylthe space 14. A. drilling machine supporting vdevice comprising a pair 4of axiallyspaced fluid pressure cylindersarranged substantially in line with one another and connected by a structure comprising Ytvvo thiniparallel plates ladjacent the sides of said cylinders and-a member joining said vplates having an aperture for receiving 'a cylindrical 'supporting arm,.m'eans .for clamping a drilling machine to the device, one ofsaidl cylinders having ally's'paced pid pressure kcylinders arranged substantiallyin line with one 'another and connect- .ed tcsaid memberyaplatforrn above said mm- `ber adapted to receive the'base of -a drilling ma'- chine, clamping means actuated by :one `of said fluid pressure cylinders forclampingly 'engaging vsaid base, clamping means aetuatediby the other oi saidffluid pressure vcylinders for'clampingly engaging said supporting arm, and' valves for 'controlling Vsaid iiuid pressure cylinders having handles operable Within the space between said cylinders. e i

l5. A drilling machine supporting. device nav- Y ing a platform for receiving the baseof a drilling 'machine ixed and movable jawseoacting Ywith "said 'base to clamp the baise on said platform,

manually adjustable means or placing said movable jaw in initialf'clamping position, and fluid pressure operated means for movingsaid jaw to iinal clamping position.

i7. 'In a Vdrilling machine supporting device, a

frame, means for removably securing a drilling machine thereto, said frame having an aperture adapting the frame to be received upon a supporting arm, a grippingfmember movable to clamp said arm within saizlraperture, guide'sfor said member, a lever'pivoted on said'frame adjacent said'guides and adapted to actuate Asaid gripping member, and a iiuidk pressure cylinder Yactuating -said lever so that the force appliedito said lever by said cylinder is multiplied sui'cientsaid `supporting device to said'arm. i

18. VIn a .drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said frame havingan aperture adapting the frame to be received upon a supapplied Vto said lever by said cylinder is multiplied sufliciently to cause the gripping'member to secure said supporting device to said arm.

19. In a drilling machine supporting device, a frame having an aperture for receiving a cylindrical supporting arm, means for removably securing a drilling machine to said frame, a uid pressure cylinder having a piston whose axis is at right angles to the axis of said aperture and spacedftherefrom, a lever actuated by said piston and pivoted on the frame of the supporting device, a movable jaw projecting into said aperture to clamp said arm in said aperture, said lever coacting with said movable jaw close to the pivot of said lever to move said jaw into clamping engagement with said arm.

20. In a drilling machine supporting device, a frame having an aperture for receiving a cylindrical supporting arm, means for removably securing a drilling machine to said frame, a fluid pressure cylinder having a piston whose axis is at right angles to the axis of said aperture and spaced therefrcm, a lever actuated by said piston and pivoted on said frame, a movable toothed jaw having the teeth thereof projecting into said aperture, a pair of lugs projecting inwardly from the wall of said aperture opposite said movable jaw, guiding means for permitting said jaw to move radially with respect to said aperture, and a cam on said lever close to the pivot thereof coacting with said movable jaw to move the same toward said lugs and exert clamping pressure sufficient to secure said supporting device upon said arm.

21. In a drilling machine supporting device, a frame structure, means for removably securing a drilling machine thereto, said frame structure including a member having an aperture for receiving a cylindrical supporting arm, a gripping member operable to clamp said arm within said aperture, a fluid pressure cylinder on said frame having a movable element, and force-multiplying mechanism connecting said element and said gripping member to move said gripping member into clamping engagement with the supporting arm.

22. In a drilling machine supporting device, a frame, means for removably securing a drilling machine thereto, said frame having an aperture adapting the frame to be received upon a supporting arm, a gripping member operable to clamp said arm within said aperture, a fluid pressure cylinder carried by the frame and having a movable element, and a lever pivoted on the frame connecting said element and said gripping member to cause the gripping member to clampingly engage the supporting arm.

23. In a drilling machine supporting device, a frame structure comprising two spaced plates and a member joining said plates having an aperture for receiving a cylindrical supporting arm, a platform above said member adapted to receive the base of a drilling machine, a fluid pressure cylinder carried by said spaced plates, a gripping member operable to clamp said arm within said aperture, a piston for the fluid pressure cylinder, and a lever pivoted between said plates for operatively connecting the piston with the gripping member to cause the same to clampingly engage the supporting arm.

24. A drilling machine supporting device having a frame comprising a pair of spaced parallel plates joined by a member having an aperture therein for receiving a cylindrical supporting arm, a platform above said member adapted to receive the base of a drilling machine, clamping means associated with said platform for securing the drilling machine thereto, a fluid pressure cylinder mounted between said plates and having its axis at right angles to the axis of the supporting arm aperture, a gripping member carried by the apertured member and arranged to be radially movable with respect to the supporting arm, and force-multiplying mechanism carried by said frame for causing the Vgripping member to be moved by the uid pressure cylinder into clamping engagement with the supporting arm.

25. A drilling machine supporting device having a frame comprising a pair of spaced parallel plates joined by a member having an aperture therein for receiving a cylindrical supporting arm, a platform above said member adapted to receive the case of a drilling machine, means for clamping the drilling machine to the platform, said member having a slot-like opening therein parallel with the axis of the aperture, a gripping member mounted to slide radially in said slot-like opening, a fluid pressure cylinder mounted between said parallel plates, and force-multiplying mechanism for causing said cylinder to actuate the gripping member to clampingly engage the supporting arm.

ARCHIBALD R. LAWRENCE. 

